Gravitational wave echoes induced by a point mass plunging to a black hole

Understand

Recently, the possibility of detecting gravitational wave echoes in the data stream subsequent to the binary black hole mergers observed by LIGO was suggested.

• Motivated by this suggestion, we presented templates of echoes based on black hole perturbations in our previous work.
• There, we assumed that the incident waves resulting in echoes are similar to the ones that directly escape to the asymptotic infinity.
• In this work, to extract more reliable information on the waveform of echoes without using the naive assumption on the incident waves, we investigate gravitational waves induced by a point mass plunging into a Kerr black hole.